Threaded boss for pressure vessel

Abstract

A boss includes a neck and a flange that extends radially outward from the neck. The neck includes a bore therethrough with a longitudinal axis. The flange includes an exterior surface, an interior surface, and a peripheral surface at a farthest extent from the longitudinal axis. The peripheral surface connects the interior surface and the exterior surface and includes, along any radius of the boss, a first circumferential ridge and a second circumferential ridge, wherein the first circumferential ridge is located closer to the exterior surface than the second circumferential ridge. In another aspect, a pressure vessel includes a boss and a liner. In yet another aspect, a method of assembling a pressure vessel is described, which includes inserting the boss through the aperture of the liner and connecting the boss and liner so that the peripheral surface of the boss mates with the perimeter surface of the liner.

What is claimed is: 
     
       1. A boss including:
 a neck having a longitudinal axis; and 
 a flange that extends radially outward from the neck, wherein the flange includes:
 a peripheral surface at a farthest extent from the longitudinal axis,
 wherein the peripheral surface includes a helical screw. 
 
 
 
     
     
       2. The boss of  claim 1 , wherein the helical screw has a substantially triangular cross-sectional shape having first and second surfaces that meet at an apex. 
     
     
       3. The boss of  claim 2 , wherein at least one of the first and second surfaces is substantially perpendicular to the longitudinal axis. 
     
     
       4. The boss of  claim 1 , wherein the helical screw has a convex curve shape. 
     
     
       5. A pressure vessel including a boss and a liner, wherein:
 the boss includes:
 a neck having a longitudinal axis; and
 a flange that extends radially outward from the neck, wherein the flange includes a peripheral surface at a farthest extent from the longitudinal axis;
 wherein the peripheral surface includes a helical screw; and 
 
 
 
 the liner includes a perimeter surface that interfaces with the peripheral surface of the boss. 
 
     
     
       6. The pressure vessel of  claim 5 , wherein:
 the boss includes an annular tab on an exterior surface of the flange; and 
 the liner includes a groove configured to accept the tab. 
 
     
     
       7. The pressure vessel of  claim 6 , wherein the tab and the groove are configured so that an interference fit is achieved at an interface of the tab and the groove. 
     
     
       8. The pressure vessel of  claim 6 , further including a gasket disposed between the tab and the groove. 
     
     
       9. The boss of  claim 1  wherein the peripheral surface is parallel to the longitudinal axis. 
     
     
       10. The boss of  claim 1  wherein the peripheral surface is inclined relative to the longitudinal axis. 
     
     
       11. The boss of  claim 10 , wherein the peripheral surface is closer to the longitudinal axis proximate an exterior surface of the flange and wherein the peripheral surface is farther from the longitudinal axis proximate an interior surface of the flange.